In existing optical modules used in the field of optical communication, the transmission direction of a light beam emitted by a laser is changed to couple the light beam to an optical fiber, or the transmission direction of a received light beam in the optical fiber is changed to couple the received light beam to a photoelectric detector. A plurality of reflectors are usually obliquely arranged to change the transmission direction of the beams. A large number of reflectors are involved, complex structures are arranged, the assembly is complicated, and the normal transmission of light signals is affected easily due to position errors. Therefore, it is proposed that an integrated optical device with multi-structural-surfaces can be adopted to achieve the direction-changing transmission of light signals. Generally, the light emitted by the laser of the optical module is relatively large in intensity and needs to be attenuated before entering the optical fiber. Such optical device with multi-structural-surfaces usually includes light-absorbing dielectric materials which are added to absorb light, so as to achieve the purpose of the light intensity attenuation. In this way of attenuating the light intensity, not only the production process is complex, but also the degree of the light intensity attenuation is difficult to control, thereby resulting in relatively low performance, relatively high cost and difficulty in producing of the optical device.